OBJECTIVES: The principal objective of this study is to clearly define the mechanisms controlling sugar metabolism in the normal mammalian lens. Having achieved this we will be able to evaluate the adequacy, stability, and possible alterations of these mechanisms in the evolving or mature experimental cataract. Ultimately, of course, we hope to study the human lens in a similar manner and perhaps define some of the mechanisms underlying senile cataract formation. Experimental models of cataract formation will be used for in-vivo and in-vitro study. The focus of our effort will be placed on anaerobic glycolysis with relevant studies of hexosemonophosphate shunt activity and its relationship to glutathione metabolism. Elucidation and characterization of points of metabolic control (i.e., hexokinase (HK) and phosphofructokinase (PFK) will be stressed through a detailed study of these individual reaction mechanisms. Hypoglycemic cataract in incubated rat lens will be studied further both as a model of regulatory mechanisms of HK and PFK activity. The collaboration of three investigators will allow intense study of many of the biochemical and physiological aspects of cataract formation and will facilitate extension and comparison of the results of animal lens studies to the human lens.